Hydraulic jar



Aug. 13, 1957 H. w. HARRISON 2,802,703

l HYDRAULIC JAR Filed Aug. 2, 1956 6 Sheets-Sheet 1 INVENTOR HAPPY W#AMP/50N ATTORNEY Aug. 13, 1957 H. w.. HARR|sN.

HYDRAULIC- JAR 6 Sheets-Sheet 2 Filed Aug. 2, 1956 INVENT OR A'ITRNEYAug. 13, 1957 H. w. HARRISON HYDRAULIC JAR e Sheets-sheet :s

Filed Aug. 2. 1956 A INVENTOR ATTORNEY A11-lg.Y 13, 1'957 Filed Aug. 2.1956 H. W. HARRISON 6 Sheets-Sheet 4 ATTORNEY Aug. 13, 1957 H. w.HARRISON 2,802,703

HYDRAULIC JAR 6 Smets-sheet v5 Filed Aug. 2, .195B

INVENTOR H/l/P/Py W A//l/P/P/SO/V Y m/Z@ ATTORNEY ug 13, 1957 H. w.HARRlsoN 2,302,703

HYDRAULIC JAR Filed Aug. 2. 195s -e sheets-sheet e fm2/ey w /e/Am/So/vA1 ATTORNEY United States Patent() HYDRAULIC JAR Harry W. Harrison,Houston, Tex., assignor to Houston Engineers, Inc., Houston, Tex.

Application August 2, 1956, Serial No. 601,730

7 Claims. (Cl. Z55-27) The present invention relates to impact tools andmore particularly to hydraulic impact tools for removing lodged objectsfrom well bores. This application is a continuation-in-part of myco-pending application, Serial No. 464,278, for Hydraulic Jar, tiledOctober 25,- 1954.

In the many operations associated with drilling and maintaining wells,such as oil and gas wells, it is a common occurrence for objects tobecome lodged within the well bore during such drilling and maintenanceoperations; detritus such as broken drills, broken sections of pipe,portions of drill `stem testers, and the like is frequently encountered.It is obvious that before any further operations can proceed or beforethe well can function properly such lodged objects must be quickly andeffectively removed. In addition to the problem of broken objectsbecoming lodged in the well it has often been the experience in oil welloperations that when testing with a drill stem tester -or drilling witha diamond core drill that the tester or drill itself ksometimes becomeslodged and must be removed by suitable dislodging means.

Prior art eiforts have resulted in many and varied types of tools forthe removal of such stuck objects from well bores. Among 'such toolsheretofore provided have been various types of jarring or impactmechanisms including hydraulic type jar tools. The most notabledisadvantage of such hydraulic jarring mechanisms heretofore used isthat such mechanisms deliver an i-mpact force in both directions ofoperation; that is, the mecha- `nism when actuated to deliver a jarringforce to the stuck object in the direction of removal also delivers :ljarring force to the object when the mechanism is reset for subsequentdislodging actions. Oftentimes the. impact force for resetting thehydraulic jar results in only further lodging or imbedding the stuckobject within the well bore. As a result of the afore-describedoperation of prior art devices, it is obvious that Whatever is gained ina dislodging action of the jarring tool islost by the resetting actionof the tool, with the net result that the removal operation is oftenlong, tedious and unduly expensive.

Evidentiary of the excessive time and cost factors are statistics thatshow it has not been uncommon for such removal operations to takeupwards to sixteen hours. And, when this dislodging time is consideredin the light of the fact that the well is shut down during theseoperations, and of the idle high-salaried personnel involved, it isobvious that the expense involved in dislodging stuck objects in wellbores by heretoforeknown mechanisms results in an exorbitant costfactor.

A further disadvantage of prior art devices is the fact that many ofthese devices embody a plurality of complicated elements whichare notonly expensive to machine but also are structurally weak and result infailure in the eld.

The present invention is .directed to an impact or ICC hydraulic jarringmechanism for dislodging objects that have been stuck in well bores.Uniquely the tool of the present invention embodies a uni-directionalimpact operation. That is, the tool of the present invention delivers animpact force only in the direction necessary to release the lodgedobject and thus embodies a novel feature for smooth non-impact resettingof the tool. It is obvious, from the afore-described, that inthe presentinvention nothing is lost by further lodging the tool during a resettingaction as heretofore experienced and describedwith prior art devices.Further, the tool of the present invention is so constructed as toembody only the simplest of machined parts having a rugged configurationto withstand the most severe operation in the iield without anypossibility of failure.

It is therefore an object of the present invention to provide a novelhydraulic impact tool.

Still another object of the present invention is to provide a novelhydraulic impact `tool that delivers unidirectional impact.

Yet another object of the present novel invention is to provide a novelhydraulic impact tool that delivers unidirectional impact and rapidlyresets with non-impact motion.

An additional object of the present invention is to provide a hydraulicimpact tool having a novel closed Huid chamber operatively mounting amovable piston whereby impact forces are imposed on the tool by movementin one direction of the piston and resetting of the piston is donewithout impact forces.

Another object of the present invention is to provide a well tool jarwhich may be quickly reset after actuation with a minimum of eifort soas to deliver repeated blows in a minimum amount of time in apredetermined direction to the stuck object.

Yet a further object of the present invention is to provide in ahydraulic jar a means for restricting movement between `spaced impactfaces and to then suddenly release or unrestrict movement so that theimpact faces may come together suddenly and deliver an impact or jarringaction to a stuck object and which means allows the jar to be quicklyreset for delivering additional blows to the stuck object.

Another object of the present invention is to provide a hydraulic toolwith novel pressure creating means and cooperating pressure responsivemeans to effect unidirectional impact action of the pressure creatingmeans and a rapid non-impact resetting of the pressure creating means.

Another object of the present invention is to provide a hydraulic toolwith novel pressure responsive means to effect an impact in onedirection and rapid nonimpact resetting action in the oppositedirection.

Yet another object of the present invention is to provide a hydraulictool with novel pressure creating means and cooperating fully movablepressure responsive means to effect a severe uni-directional impactaction upwardly and a smooth, rapid, non-impact downward resettingaction.

An additional object of the present invention is to provide a hydraulictool with a closed iluid chamber having relatively movable pressurecreating and pressure responsive means therein for effectinguni-directional impact action for releasing a stuck object and rapidnonimpactresetting action' to prevent further lodging of the stuckobject during a resetting action ofthe tool.

Still a further object of the present invention is to provide a`uni-directional impact tool with novel ytorque means to permit rotationof the entire tool for connection to either another tool element or astuck object.

A .still further object of the invention is to provide ya 3 hydraulicjar which includes a movable barrier to restrict movement of uid in onedirection in the tool, but which does not restrict movement of fluid inthe other direction in the tool.

Yet a further object of the invention is -to provide a hydraulic jarwhich delivers a maximum number of impacts in a predetermined directionin a minimum amount of time.

Still a further object of the present invention is to provide auni-directional hydraulic impact tool that is of rugged construction,has prolonged service life, is simple to operate, and delivers maximumeciency over an extended period of service life.

These and other objects will become more apparent when read inconjunction with the following detailed description and the attacheddrawings, wherein:

Figure 1 is a fragmentary vertical sectional view of of a preferredembodiment of the present invention will an upper portion of a preferredembodiment of the present 'Y invention showing the novel uid piston andnovel movable sleeve mounted in a closed hydraulic chamber whichelements cooperate to deliver the impact forces and rapid resetting ofthe tool.

Figure 2 is a vertical sectional View of the lower portion of thepreferred embodiment of the present invention showing the guide meansfor the novel mandrel or shaft and also showing the means for attachmentof the present tool to a suitable tishing tool or the like.

Figure 3 is a horizontal sectional view taken substantially along theline 3 3 of Figure 1.

Figure 4 is a horizontal sectional view taken substantially along theline 4-4 of Figure 1.

Figure 5 is a fragmentary vertical sectional view of one embodiment ofthe tool showing the relative position of the parts at the time ofdelivery of the impact or jarring action of the tool.

Figure 6 is a fragmentary vertical sectional view similar to that shownin Figure 5, but showing the tool during a resetting operation prior tothe delivery of a successive impact stroke.

Figures 7 through 10, inclusive, are vertical sectional schematic viewsshowing successive positions of the novel piston and sleeve during thedelivery of an impact stroke.

Figures 11 through 14, inclusive, are vertical sectional schematic viewsshowing the successive positions of the piston and the novel movablesleeve during a resetting operation of the present invention.

Figure 15 is a vertical sectional View, somewhat enlarged in horizontaldimensions for illustrative clarity, of the upper portion of a furtherform of the present novel invention, showing novel torque means andnovel means of connection to the mandrel.

Figure 16 is a vertical sectional view of the intermediate portion ofthe tool shown in Figure l5, and further showing the preferred form ofmovable sleeve.

Figure 17 is a vertical sectional view or the lowermost portion of thetool shown in Figures 15 and 16, and showing the means of connecting thetool to another form of tool such as a shing tool, diamond core drill,or the like.

Figure 18 is an enlarged elevational view of the novel movable sleeveshown in Figure 16.

Figure 19 is a horizontal sectional View taken substantially along theline 19--19 of Figure 18.

Figure 20 is a horizontal sectional view taken substantially along theline 20-20 of Figure 15.

l Figure 2l is a horizontal sectional view taken substantially along theline 21-21 of Figure 16.

Figures 22 through 25 inclusive, are vertical sectional schematic viewsof successive positions of operation of the second form of tool duringthe delivery of an irnpact force, and

Figures 26 through 29 inclusive, are successive vertical sectionalschematic viewsof a resetting action of the novel tool shown in Figures15 through 17.

Turning now to Figures 1 and 2 a detailed description now be given. Asclearly seen in Figure 1, the novel impact or jarring tool of thepresent invention is generally indicated by the numeral 20. Tool 20consists of a pair of hollow outer body members 22 and 24, respectively,internally threaded at their respective ends as indicated by the numeral26. Threadedly mounted at the upper end of hollow body 22 is a hollowseal mounting member 28 internally threaded as at 30 and having aninternal inwardly extending guide shoulder 32 for a purpose to behereinafter described.

Threadedly inter-connecting the lower end of body portion 22 with theupper end of body portion 24 is another seal member 34, havinginternally directed guide shoulders 36 and also being internallythreaded as at 38 for a purpose to be hereinafter described. The lowerend of body portion 24 is threadedly connected to connector member 40,which is provided with an axially extending bore 42 for a purpose to behereinafter described, and external pipe threads 44 for the purposes ofconnecting the tool 20, of the present invention, to a fishing tool,diamond drill, or other, suitable tool.

Mounted within counter bore 46 of seal member 28 are a plurality ofaxial or annular sealing members 48 which 'are compressed betweenshoulder 32 and a seal gland nut 50 threadedly mounted on threads 30 ofseal member 28. Gland nut 50 is provided with an axial bore 52 in axialalignment with the bore 53 dened by inwardly directed shoulder 32, for apurpose which will hereinafter be described. Similarly, seal members 54are mounted in counter bore 56 of seal member 34 and compressed betweenshoulder 36 and gland nut 58 threadedly mounted on threads 38 of sealmember 34. Gland nut 58 also has an axial bore 60 in line with and ofthe same dimension as the bore 61 through shoulder 36 of seal member 34,for a purpose which will hereinafter appear.

The space between shoulder 36 of seal member 34 and the under face 62 ofseal member 28 defines a closed hydraulic chamber designated 64 whichserves to mount a novel impact mechanism Which Will now be particularlydescribed.

Mounted within hydraulic chamber 64 is a novel hollow cylindrical ortubular sleeve having a close sliding t with the sidewalls of chamber64, this sleeve being generally designated by the numeral 66. The upperand lower ends of sleeve 66 are provided with a plurality ofcircumferentially equally spaced fluid by-pass means or slots 68 and 70,respectively. The length of said slots is approximately one-third of thelength of sleeve 66, thereby leaving an un-slotted portion 72 ofapproximately one-third the length of sleeve 66 for a purpose whichshall appear.

Slidably mounted within the bores S3 and 61 deiined by shoulders 32 and36, respectively, and bores 52 and 60 of gland nuts 50 and S8,respectively, is an elongate mandrel member 73 having an axiallyextending bore 74 and also having upper and lower threaded ends 76 and78, respectively, for a purpose which will appear. Threadedly connectedto the upper end of mandrel 73' is a connector member having internalpipe threads 82 for suitable connection to a drill string and having anlaxially extending bore 84 in alignment with bore 74 of mandrel 73.`Connected to threadv78 at the lower end of mandrel 73 is a guidemounting member 86, which will be described in detail hereinafter.Formed on mandrel 73 intermediate shoulder 36 and face 62 is an enlargedpiston portion 88 which cooperates with novel movable sleeve 66 fordelivering the impact forces as will hereinafter appear. The internaldiameter of sleeve 66 is somewhat larger than the external diameter ofpiston 88 to,v thereby define a small annular passage 90 between sleeve66 and piston 88 for a purpose which'will hereinafter more fully appear.

Turning momentarily'to the lower portion of Figure 1 and to Figure 2,attention is directed to the fact that seal member 34 is provided with'lan integral downwardly ex. tending sleeve portion' 92 whichextendsfsubstantiallythe full length of housing 24 andl terminatesjust'short of the inner end of connector member 40 asrclearly seen inFigure 2. Intermediate upper and lower solid cylindrical portions 94 and96, respectively, sleeve`92 is provided with a pair of diametricallyopposed slotted portions 98 extending substantially the full length ofsleeve 92 to serve as a novel guide means for mandrel 73 as will be nowparticularly described. k

As clearly seen at the lower en'dofkFigure 2, guide mounting member 86is provided 'with a pair of diametrically oppositely extending wingsorlugs 100 having a span of just slightly less than the internaldiameter of housing or body portion 24 and a width just slightly lessthan the width of slots 98. Lugs 100 slidably lit in slots 98 to therebyguide axial sliding'movements of mandrel 73, and in addition, slots 98and their cooperative lugs 100 permit rotative action of the entire tool20 to permit connection of connector 40 by means of threads v44 to afishing tool, diamond drill, or other tool that may be in the well.Since rotation of upperconnector member 80 will be transmitted tomandrel 73 by virtue of the rigid threaded connection therebetween,'such rotational force will be transmitted from the mandrel 75 to lugs100 and to sleeve portion 92 of seal mounting number 34 therebytransmitting rotative force tothe entire tool 20. Guide mounting memberA86 is also provided with a through bore 102 in axial alignment withbore 74 of mandrel 73 and bore 42 of connector body 40 to provide a uidpassage through the entire'tool 20 to permit the passage therethrough ofa wash fluid or other suitable iiuid media for whatever purpose it maybe used.

It is obvious from the foregoing detailed description that annular axialseals 48 and 54 are 'eiectively seal off the ends of chamber 64 todefine a closed uid'or hydraulic chambery This chamber is filled with ahydraulic fluid for cooperative actionwith sleeve 66 and piston 88 for apurpose which will now fully appear in connection with a description ofthe novel operation of the tool of the present invention.

Turning to Figures 5, and 7 through 10, the operation of the tool whiledelivering an impact force to dislodge an object in the well will now beparticularly described. In operation a shing tool can be threaded toconnector member 40 as heretofore described or the tool can be loweredinto a well and rotated so that threads 44 of connector member 40can-threadedly engage the upper end of a sh, grapple, drill, or thelike, which may already be within the well and desiredkto be retrieved.Once the appropriate connection has beenmade between tool 20 and anothertool, the .tool-'20l is then ready for operation to deliver its novelimpact dislodging action to any vobject lodged within the well. 'f

Turning now to Figures and'7 through 10, inclusive, a detaileddescription of the operation of the tool during the delivery of animpact or dislodging action Vwill now be given. With the toolappropriately connected to the lodged object or shing tool, as the casemayA be, an upward pull is exerted on the drill stringv (not shown)which upward pull is transmitted to upper connector member 88 and fromconnectorfmember 80 to mandrel 73 by virtu-e of the connection betweenmandrel 73 and 'connector member 80, as heretofore described. Initially,upward movement of the drill string and mandrel 73 is accompanied by anupward movementofpiston 88 until the upper end of the piston v88`5iscoincident with the upper ends of lower slots 70 of movable 'sleeve 66.At this point of relative position of piston 88 and sleeve 66 fluid flowfrom above the piston to beneath thepiston is restricted by virtue ofsubstantial cutoff of slots 70 by piston v88. As a result furthermovement of piston 88 upwardly lrelative to sleeve 66 results in acompressive force being transmitted to the hydraulic uid above piston88.

*Since the fluid above piston 88 can only slowly drain to .the lowerside of piston 88 through the small or restrictive passages98 about orbetween piston 88 and sleeve 66 the `movement of piston 88 upwardlythrough the unslotted portion 72 of sleeve 66 is substantially retarded,and as a result of this retarded movement a tensile stress is 4appliedor stored in the drill string resulting in an elongation of the drillstring.

Movement of piston 88 through the unslotted portion 72. of sleeve 66 isobviously very slow due to the slow draining of uid above the piston 88through the passage 90 to the underside of the piston. As the lowermostend of piston'SS nally clears the uppermost end of unslotted portion 72there is a rapid ow of hydraulic fluid from the upper end of piston 88or the upper end of chamber 64 through the now opened slot 68 to thelower end of chamber 64 and as a result the retarding or resisting iowforce of the fluid is dissipated and due to the tensile stresses storedin the drill string and the no longer restricting force of the hydraulicfluid in the upper portion of chamber 64, the piston 88 moves upwardlywith tremendous rapidity and the uppermost end of piston 88 designatedby the knumeral 104 impacts or contacts the face 62 of seal member 28with a severe upward impact force resulting in a dislodging pull orupward pull on the lodged object connected to either connector member 40or the sh which is mounted on connector member 40. In this manner atremendous impact or dislodging movement is exerted upwardly on thelodged object within the well bore to effect release of the lodgedobject.

It can be readily appreciated that, throughout the upward movement ofpiston 88 in -chamber 64, after it clears sleeve 66, movable sleeve 66remains at its lowermost position in chamber 64 due to the force of thelluid therein exerting itself upon the upper end of sleeve 66 forcingthe sleeve downwardly. Therefore, the only movement during the deliveryof the impact .force is the upward movement of the piston 88 relative tosleeve 66.

In order to reset the piston 88 at the lowermost end of chamber 64 for asuccessive impact action reference should be had to Figures 6 and l1through 14, inclusive. During a resetting action the drill string andconsequently mandrel 73 are moved downwardly which results in downwardmovement of piston 88. During the downward movement of piston 88 thereis a compressive force exerted on the hydraulic fluid beneath `piston88. As La lresult of this downward movement the fluid pressure stored inthe fluid beneath piston 88 is also exerted on the underside of movable`sleeve, 66 and as the piston 88 moves downwardly the hydraulic pressuremoves the sleeve upwardly relative to the piston 88 as clearly seen inFigure l2. Therefore there is a rapid relative movement of piston 88with respect to sleeve 66 and there is no retarding action due to thecompression of fluid and a limited escape means since, as piston 88compresses the fluid, sleeve 66 constantly moves upwardly leaving anexpanded chamber for the dissipation of the uid pressure. Once theuppermost end of piston 88 clears the lowermost end of unslotted portion72 of sleeve 66 there is an even greater dissipation of fluid pressuresince the fluid can now flow from the lower end of chamber 64 throughslots 70 to the upper side of Vpiston 88 and as a result thereof piston88 will be rapidly moved to its lowermost or reset position without eventhe slightest indication of an impact force being exerted downwardly onthe tool, and conse- It is obvious from the foregoing and a study ofFigures 7 through )14 that the present invention provides a novel meansof delivering a uni-directional impact force for removing lodged objectswhile providing an absolute smooth rapid resetting of the tool withoutthe delivery of any negative impact forces which could only furtherlodge the object within the well bore.

As a result of the foregoing the tool of the present invention herebyfacilitates the removal of lodged objects from wells in a minimum amountof time and with a maximum efficiency and the tool as heretoforedescribed is of relatively simple construction that is rugged and easilymaintained in the field and simple to operate.

Turning now to Figures l through 17, a further form of the presentinvention will be particularly described, the figures being slightlyexaggerated in horizontal dimension for illustrative clarity of certainsmall detail parts. The numeral 200 generally designates the novelhydraulic tool of the present embodiment consisting of an outer hollowhousing member consisting of sections 2027 204 and 206, eachinterconnected as will hereinafter be described, to define upper,intermediate, and lower body portions of novel tool 200. The lowermostinternal end of section 202 is internally threaded as at 208 while theupper internal end of intermediate section 204 is internally threaded asat 210 in order that externally threaded intermediate connector member212 can be threaded into the lower end of section 202 and the upper endof section 204 to connect these sections together as clearly seen inFigures and 16.

The lowermost end of intermediate section 204 is similarly internallythreaded as at 214 for receiving the upper externally threaded end ofsection 206 in order that sections 204 and 206 can also be threadedlyinterconnected. Similarly the lower end of section 206 is internallythreaded as at 216 for threadedly receiving externally threadedconnector member 218 which is provided with external pipe threads 220for suitable connection to a fishing grapple, diamond drill, drill stemtester, or the like.

The uppermost end of section 202 is provided with a counterbore 222interconnected by means of countersink 224 to axial extending bore 226which opens into cylindrical chamber 228 within section 202. As clearlyseen in Figure 15 the uppermost limit of cylindrical chamber 228 isdefined by the inwardly exposed annular face 230 which defines an impactface as will hereinafter more fully appear. At the uppermost andlowermost ends of cylindrical chamber 228 there are provided upper andlower diametrically opposed drain holes 232 and 234 respectively7 forpurposes of draining an accumulation of uid within chamber 228 as willhereinafter more fully appear. The lowermost limit of cylindricalchamber 228 is defined by the inwardly directed face 236 of intermediateconnector member 212.

As best seen in Figure 16 section 204 is provided adjacent its upper endwith an inwardly directed annular shoulder 238 defining a circular bore240 therethrough which serves as a guide means as will hereinafter bemore particularly described.

Slidably disposed within section 204 between the upper end of annularshoulder 238 and the lower end of intermediate member 212 are annularsealing rings 246, 248, and 252. The innermost end or slide of annularshoulder 238 is countersunk or biased as indicated by the numeral 254.Shoulder 238 defines the upper limit of a closed hydraulic chamber 256whose function is similar to hyi draulic chamber 64 of Figure 1, as willhereinafter become apparent.

As clearly seen at the lower end of Figure 16, the upper threaded end ofsection 206 is provided with an annular groove for the reception of asealing element 258 similar in construction to one of the sealingelements 252, 246, and 248 above shoulder 238 at the top of chamber 256.In addition, section 206 is provided with an internal annular groove forthe mounting of annular seal ring 260 within bore 262 of section 206,while an external annular groove is provided in section 206 just beneaththreads 214 for the mounting of an annular seal rin'g264 therein, toprevent leakage from :section 204 to section 206. Bore 262 atY the upperend of sec-tion 206 is interconnected with enlarged bore or chamber266of section 206 by means of countersunlt portion 268 as clearly seenin Figure 16. Chamber 266 is defined at its lower vend by the inner face270 of connector member 218 which isalso provided with an axial extending bore 272 having a countersunk portion 274 in axial alignmenttherewith at its upper end, for a purpose to be hereinafter described.

Attention is now directed to Figure 20 in conjunction with Figure 15wherein it will be seen that bore 226 at the upper end of section 202 isprovided with diametiically opposite or opposed fiat surfaces 276defining chords of a circle of a diameter of bore 226, which serve asguide surfaces for a novel mandrel as will be now particularlydescribed.

As clearly seen in the upper portion of Figure 15 there is provided asubstantially cylindrical connector member 278 having an internallythreaded pipe thread portion 280 terminating in a countersunk portion282 which is in axial alignment with axially extending bore 284 ofintegral elongate mandrelV portion 286. As clearly seen in Figure 20 thecross section of integral elongate mandrel portion 286 conforms exactlyin cross section to the configuration defined by fiat sides 226 andarcuate sides 276 of the bore portion heretofore described. Thus thefiat portions of mandrel 286 are guided by fiat portions 276, and inaddition serve as a torque transmitting device as will hereinafter morefully be described. The lowermost end of elongate mandrel section 286 isthreaded as at 288, so as to threadedly engage the upper end ofinternally threaded mandrel-connector member 290. In addition thelowermost end of mandrel 286 is provided with an external annular groovefor the mounting of annular sealing ring 292 which cooperates with theinternal diameter of connector member 2.90 to prevent any leakagetherebetween.

As clearly seen in Figure 15 intermediate shoulder 294 of mandrelconnector 290 is provided with axial bore 296 in alignment with bore 284of elongate mandrel 286. The upper end of intermediate mandrel 298 isprovided with an external annular groove for the mounting of annularsealing ring 300, and is also externally threaded as at 301 forconnection to the lower internally threaded portion of mandrel connector290. Intermediate mandrel 298 is provided with an axially extending bore306 which is in connection with and in alignment with bores 284 and 296heretofore described. The lower end of intermediate mandrel 298 isinternally threaded as at 308 for receiving the upper threaded end oflower mandrel section 310 which is provided with an external annulargroove above its threaded portion for the mounting of annular sealingring 312 in order to prevent leakage past mandrel sections 298 and 310,respectively.

Attention is particularly directed to the lowermost end of intermediatemandrel portion 298 wherein it is clearly seen that this lowermost endis provided with an enlarged cylindrical boss `314'having acircumferential shoulder 316 at its upper end which defines a fluidpiston for purposes of compressing a hydraulic fluid (not shown) inchamber 256 as will hereinafter become more apparent.

Slidably mounted within hollow chamber 256 is a movable sleeve 318operatively interposed between the outside diameter of piston 314 andthe inner wall of chamber 256, this sleeve functioning in essentiallythe same manner as sleeve 66 shown in Figure 1.

Turning now to Figure 18, the novel sleeve 318 of Figure 16 will now bemore particularly described. As clearly seen in Figures 18 and schematicFigures 23 through 30, the upper portion of sleeve 318 is a tubular orhollow cylindrical portion 320 having a smooth internal bore 322slightly larger than the outside diameter of piston 314,to definetherebetween a restricted fiuid passage 324 comparable to passage ofFigure 1. The

lowermostvportion 326 ofsleeve 318 is provided with circumferentia'lly.equally.l spaced inwardly directedf slotted portions 328 which are,essentially similar to slots 70 at the lower end of sleeve 66illustrated in Figure 1. `Mounted within the bore 322 of sleeve 318 isan annular ring 330 whose lowermost face332 is coincident or in the sameplane with the lowermost face or end 334 of sleeve 318. Annular ring 330is xedly secured to the lowermostportion 326 of ring 318, `as by brazingor welding for a purpose to be more fully hereinafter described.

Turning now to Figures 22 through 25 a progressive step by stepoperation during the delivery of an impact force of the tool shown inFigures through 17 will now be'particularly described. n

kFigures 22 through 25` illustrate a lstep by step schematicrepresentation of the operation of the novel tool of Figures 15through17 during the delivery of an impact or dislodging action.

Once'the tool 200 has been secured to a grapple or to a lodged object apull is exerted at the surface on the drill string `(notshown), whichupward pull is transmitted to the mandrel 298. Initially upward pull onthemandrel is easily accomplished, since at rst the oil above the piston314 will be forced through slots 328 to the underside of the piston 314.However, once the upper end of piston 314 cuts olf or closes the slots328 the only way that the hydraulic uid above piston 314 can escape tothe underside of the piston is through the very vnarrow annular passage324 between piston 314 and the inner wall of the upper part 320 of thesleeve 318. Since passage 324 is very small the ow of hydraulic uidtherethrough is very slow, and consequently there is a compressive forceexerted by piston 314 on the hydraulic fluid thereabove.

The `pull on the drill string varies anywhere from 30,000 to 90,000pounds above the weight of the string and connected piping. Since thereis a high resistance resulting from the compression of the hydraulicfluid there is an elongation or storing up of tensile stresses in thedrill string. With the tensile stresses being exerted in :the drillstring, oil or other hydraulic fluid slowly bleeds through the passage324, and the piston 314 slowly moves through the unslotted portion 320of sleeve 318 due to the elongation of the drill string which exerts apull on mandrel 298. Once the lowermost end of piston 314 clears theupper end of sleeve 318 there obviously is an opportunity for a rapiddissipation pressure or resistance to movement of piston 314, since theoil or other hydraulic fluid in the upper portion of chamber 256 canquickly flow past the underside of piston 314 to the lower portion ofchamber 256. With this rapid dissipation of pressure or loss ofresistance to piston movement the piston 314, and of course the mandrelsections 286 and 298, move with sudden rapidity upwardly due to thetensile stresses stored in the elongated drill string.

As a result of this very sudden and rapid upward movement due to therelease of pressure resistance the upper end 291 of intermediate mandrelconnector 290 contacts the surface 230 with a severe and suddendislodging impact, as can be readily appreciated by reference to Figurel5. As a result a sudden dislodging force is transmitted through tool200 to the device connected thereto, through connection with connectormember 218.

It will be readily appreciated from a study of Figures 22 through 25that throughout the upward movement of piston 314 that the sleeve 318remains down or at the lowermost position in chamber 256. Thispositioning of sleeve 318 is due to the fact that during upward movementand compressive action of the uid above piston 314, :that the lluidexerts a downward pressure on the uppermost ends of sleeve 318 holdingthe sleeve in the, position illustrated in Figures 22 through 25.

Turning now to Figures 26 through 29 the novel, rapid,

smoothmesetting of the tool will now be-particularly described. Themandrel 298 and consequently the piston l314 are moveddownwardly'upondownward movement of the drill string. This downward movement alsoresults ina compression ofthe hydraulic. fluid beneath the piston 314.However, Vas-the fluid is compressed pressure is exerted on theunderside of sleeve V318 Ycausing the sleeve 318 .to move upwardlyrelative to :the downward movement of piston 314. As a result, there isa constant expanding chamber beneath piston 314 for pressure dissipationso that the relative movement of piston 314 and sleeve 318 is verysmooth `and rapid, contrary to the heretofore described slow` resistedupward movement.

Attention is directed to Figures 26 and 29 wherein it is clearly seenthat sleeve 318 does not move to the uppermost end of chamber 256, asdoessleeve 66 'in chamber 34, because ring 330 prevents piston 314 fromkpassing clear throughsleeve 318. When piston 314 abuts kends of sleeve318 preventing undue warping or expansion thereof due to the highpressures exerted within chamber 256.

The degree of elongation ofthe drillstring or time delay during yanupward impact pull of the tool `can be varied very easily by thevariation of one of four variable features of the present invention.These variables are the viscosity of the fluid used within the closedhydraulic chambers 66 or 256, the dimensioning of the annular spaces 90or 324, the clearance between the sleeve and the inner wall of thechamber, and the length of the unslotted portion of the sleeves.

Turning now to Figures 15 and 20 the purpose or function `of the noveltorque mechanism of this embodiment will now be particularly described.As heretoforev described the upper portion of section 202 is providedwith a bore defined by a pair of ilat sides 226 and a pair of arcuatesides 276. The mandrel 286 which passes through this bore conformsexactly in cross-section to this bore, thus the arcuate sides 276 are insliding contact with similar arcuate sides on the mandrel 286. When itis desired to rotate tool 200 to connect it to a grapple or otherobject, rotation of upper connector member 278 will be transmittedthrough mandrel 286 to housing section 202 and consequently housingsections 204 and 206, and finally to connector member 218, therebypermitting threaded connection of member 218 to whatever object tool 200is to be connected. The torque device as herein disclosed is of ruggedand simple construction, involving the simplest of machined parts andsusceptible of the severest type of usage.

It will be readily appreciated from the foregoing description that thereis herein provided a novel, inexpensive, easily assembled and highlyeicient impact tool that develops maximum impact forces in a singlepositive direction and permits rapid, smooth, non-impact resetting of`the tool. In addition there is also herein disclosed novel tool meansembodying torque means which contribute to la maximum efficiency lof thetool.

The invention may be embodied in other forms without departing from thespirit or essential characteristics thereof. The present embodimentsare, therefore, to be considered in all respects as illustrative and notrestrictive, the scope of 'the invention being indicated by the appendedclaims rather than by the foregoing description, and all changes whichcome within the meaning and 11 range of equivalency of the claims aretherefore intended to be embraced therein. n

What is claimed and desired to be secured by United States LettersPatent is:

1. A uni-directional jarring tool comprising a body having a closedfluid chamber'therein; a non-compressible fluid medium in said chamber;a piston movably mounted in said chamber adapted to be connected to anelevating mechanism; a freely oating annular sleeve mounted in saidchamber adjacent the wall of the chamber but spaced therefrom insurrounding relation to said piston; said sleeve being normallypositioned at one end of said chamber; said piston having its exteriorsurface adjacent to but spaced from the interior wall of said sleeve,said sleeve being of a length substantially less than the length of theuid chamber and `substantially longer than the length of said piston;whereby the sleeve is movable longitudinally relative to said wall andthe piston is freely movable longitudinally relative to said sleeve;means providing a hammer carried by said piston; means providing ananvil carried by said body; and fluid-by-pass means in the lower portionof said sleeve, said by-pass means being operable to allow fluid ow frombelow said piston to above said piston as said piston is moveddownwardly into said sleeve, whereby upward movement of the piston tendsto force the fluid medium thereabove through the restricted spacesbetween the chamber, the sleeve, and the piston to retard such upwardmovement of the piston until the piston completely emerges from saidsleeve, whereupon the fluid above the piston is caused to ow freely intothe space below the piston and said hammer strikes said anvil with asudden impact action.

2. The device as set forth in claim 1, wherein said piston is connectedvto a mandrel, and cooperating means on -said body and said mandrelpermitting axial movement of one with respect to the other andpreventing rotative movement of one with respect to the other.

3. The device as set forth in claim 1, wherein said sleeve is providedwith a radially inwardly extending ring von the bottom thereof, wherebysaid piston engages said ring to move said sleeve as a unit therewithon-downwardrnove ment of the piston to reset the piston and sleeve.

4. A device as set forthV in claiml', wherein said anvil and hammer arelocated exteriorly of said closed -uid chamber. l

5` A device as set forth in claim 1, wherein mandrels extend upwardlyand downwardly from said piston and spaced annular seal means aremounted in said body so as to embrace said mandrels. l v l 6. A deviceas set forth in claim l, wherein said wall of the closed fluid chamberhas a smooth internal bore extending throughout its axial extent, andwherein said sleeve has a smooth external and internal surface throughout its axial extent, and wherein said piston has a smooth externalsurface throughout its axial'extent. 1 l f 7. A device as set forth inclaim l, wherein said by-pass means are in the form of circumferentiallyspaced slots extending axially from the bottom end of said sleeve to apoint below the top end thereof. f

References Cited in the tile kof this patent I UNITED STATES PATENTS Re.23,354 Storm Apr. 10, 1951 1,637,505 Wigle Augj2, 1927 1,803,732 Shater,May 5, 1931 1,804,700 Maxwell May 12, 1931 2,205,910 Raybould June 25,1940 2,643,147 Funkhouser et al June 23, 1953 2,645,459 Sutlifrr Iuly14, 1953 2,647,778 Shields Aug. 4, 1953 2,721,056 Storm Oct. 18, 19552,733,045 Burns Jan. 3l, 1956

